import assert from 'node:assert/strict';
import { chmod, copyFile, mkdir, readFile, rm, symlink, writeFile } from 'node:fs/promises';
import os from 'node:os';
import path from 'node:path';
import { spawnSync } from 'node:child_process';
import test from 'node:test';

const verifier = path.join(process.cwd(), 'scripts', 'gate-verify.mjs');
const fixtureBase = path.join(process.cwd(), '.mosaic-test-work', `gate-verify-${process.pid}`);

async function fixture(name = 'case') {
  const root = path.join(fixtureBase, name);
  await rm(root, { recursive: true, force: true });
  await mkdir(path.join(root, 'gates'), { recursive: true });
  return root;
}

function baseManifest() {
  return {
    schemaVersion: 1,
    activationCommit: null,
    gateRoots: ['gates'],
    governingClaimFiles: [],
    coverageBoundary: { included: ['meta fixture'], excluded: [], trackedBy: 'RM-54' },
    criteria: [
      {
        id: 'META-CRIT-1',
        originalText: 'The fixture rejects its bad input.',
        currentText: 'The fixture rejects its bad input.',
        claimType: 'integrity',
        source: 'fixture',
        meaningChanges: [],
        caseRefs: ['meta-fixture/rejects-bad-input'],
      },
    ],
    compatibilityScenarios: [],
    proseClaims: [],
    gates: [
      {
        id: 'meta-fixture',
        source: 'gates/meta-fixture.sh',
        invocation: ['gates/meta-fixture.sh'],
        deployment: { kind: 'none', reason: 'test fixture only' },
        inertMutation: {
          file: 'gates/meta-fixture.sh',
          find: 'exit 7',
          replace: 'exit 0',
          expected: { exitCode: 0 },
        },
        cases: [
          {
            id: 'rejects-bad-input',
            criterionIds: ['META-CRIT-1'],
            mustFail: true,
            invocation: ['gates/meta-fixture.sh'],
            required: { exitCode: 7 },
            actual: { exitCode: 7 },
            reasonPattern: 'META_REJECT',
          },
        ],
      },
    ],
  };
}

async function writeGate(root, contents = '#!/bin/sh\necho META_REJECT >&2\nexit 7\n') {
  const target = path.join(root, 'gates', 'meta-fixture.sh');
  await writeFile(target, contents);
  await chmod(target, 0o755);
}

async function writeManifest(root, manifest) {
  await writeFile(path.join(root, 'gates', 'gates.manifest.json'), `${JSON.stringify(manifest)}\n`);
}

function verify(root, extraArgs = []) {
  return spawnSync(
    process.execPath,
    [
      verifier,
      '--root',
      root,
      '--manifest',
      'gates/gates.manifest.json',
      '--skip-history',
      ...extraArgs,
    ],
    { cwd: root, encoding: 'utf8', env: { ...process.env, HOME: os.homedir() } },
  );
}

function output(result) {
  return `${result.stdout}\n${result.stderr}`;
}

test.after(async () => {
  await rm(fixtureBase, { recursive: true, force: true });
});

test('an externally inerted failure branch makes verification nonzero and names the gate', async () => {
  const root = await fixture('external-inert');
  await writeGate(root, '#!/bin/sh\nexit 0\n');
  await writeManifest(root, baseManifest());

  const result = verify(root);
  assert.notEqual(result.status, 0);
  assert.match(output(result), /meta-fixture/);
});

test('the verifier applies the declared inert mutation and observes its own control red', async () => {
  const root = await fixture('internal-meta');
  await writeGate(root);
  await writeManifest(root, baseManifest());

  const result = verify(root);
  assert.equal(result.status, 0, output(result));
  assert.match(output(result), /META-NEGATIVE-CONTROL.*meta-fixture.*observed red/i);
});

test('a mutation crash is rejected instead of counted as an observed-red control', async () => {
  const root = await fixture('mutation-crash');
  await writeGate(root);
  const manifest = baseManifest();
  manifest.gates[0].inertMutation.replace = 'this is not valid shell (';
  manifest.gates[0].inertMutation.expected = { exitCode: 0 };
  await writeManifest(root, manifest);

  const result = verify(root);
  assert.notEqual(result.status, 0);
  assert.match(output(result), /meta-fixture.*mutation.*unexpected outcome/i);
  assert.doesNotMatch(output(result), /META-NEGATIVE-CONTROL.*observed red/i);
});

test('a stale declared mutation case id is rejected instead of falling back', async () => {
  const root = await fixture('stale-case-id');
  await writeGate(root);
  const manifest = baseManifest();
  manifest.gates[0].inertMutation.caseId = 'case-that-does-not-exist';
  await writeManifest(root, manifest);

  const result = verify(root);
  assert.notEqual(result.status, 0);
  assert.match(output(result), /meta-fixture.*case-that-does-not-exist.*not found/i);
});

test('duplicate stable ids and unsupported schema versions are rejected', async () => {
  const root = await fixture('closed-schema');
  await writeGate(root);
  const manifest = baseManifest();
  manifest.schemaVersion = 99;
  manifest.criteria.push({ ...manifest.criteria[0] });
  await writeManifest(root, manifest);

  const result = verify(root);
  assert.notEqual(result.status, 0);
  assert.match(output(result), /unsupported schemaVersion 99/i);
  assert.match(output(result), /duplicate criterion id META-CRIT-1/i);
});

test('manifest-controlled fixture paths cannot escape the sandbox', async () => {
  const root = await fixture('path-traversal');
  await writeGate(root);
  const manifest = baseManifest();
  manifest.gates[0].cases[0].fixture = {
    writeFiles: [{ path: '../../escaped-by-manifest', content: 'bad' }],
  };
  await writeManifest(root, manifest);

  const result = verify(root);
  assert.notEqual(result.status, 0);
  assert.match(output(result), /path escapes sandbox/i);
});

test('fixture writes reject a final symlink and preserve its outside target', async () => {
  const root = await fixture('final-symlink');
  await writeGate(root);
  const outside = path.join(fixtureBase, 'outside-sentinel');
  await writeFile(outside, 'preserve-me\n');
  const linked = path.join(root, 'linked-sentinel');
  await symlink(outside, linked);
  const manifest = baseManifest();
  manifest.gates[0].cases[0].fixture = {
    writeFiles: [{ path: 'linked-sentinel', content: 'overwritten\n' }],
  };
  await writeManifest(root, manifest);

  const result = verify(root);
  assert.notEqual(result.status, 0);
  assert.match(output(result), /fixture write.*symbolic link/i);
  assert.equal(await readFile(outside, 'utf8'), 'preserve-me\n');
});

test('an executable below a gate root without an entry is rejected', async () => {
  const root = await fixture('unregistered');
  await writeGate(root);
  const extra = path.join(root, 'gates', 'forgotten.sh');
  await writeFile(extra, '#!/bin/sh\nexit 1\n');
  await chmod(extra, 0o755);
  await writeManifest(root, baseManifest());

  const result = verify(root);
  assert.notEqual(result.status, 0);
  assert.match(output(result), /unregistered gate.*forgotten\.sh/i);
});

test('a must-fail case without a reason diagnostic is rejected', async () => {
  const root = await fixture('missing-reason');
  await writeGate(root);
  const manifest = baseManifest();
  manifest.gates[0].cases[0].reasonPattern = '';
  await writeManifest(root, manifest);

  const result = verify(root);
  assert.notEqual(result.status, 0);
  assert.match(output(result), /meta-fixture.*rejects-bad-input.*reasonPattern/i);
});

test('a gate with zero must-fail cases is rejected', async () => {
  const root = await fixture('no-negative');
  await writeGate(root, '#!/bin/sh\nexit 0\n');
  const manifest = baseManifest();
  manifest.gates[0].inertMutation = {
    file: 'gates/meta-fixture.sh',
    find: 'exit 0',
    replace: 'exit 1',
  };
  manifest.gates[0].cases = [
    {
      id: 'positive',
      criterionIds: ['META-CRIT-1'],
      mustFail: false,
      invocation: ['gates/meta-fixture.sh'],
      required: { exitCode: 0 },
      actual: { exitCode: 0 },
      reasonPattern: '',
    },
  ];
  await writeManifest(root, manifest);

  const result = verify(root);
  assert.notEqual(result.status, 0);
  assert.match(output(result), /meta-fixture.*no negative control/i);
});

test('reordered but equivalent outcome fields do not create a false behavior delta', async () => {
  const root = await fixture('reordered-outcomes');
  await writeGate(root);
  const manifest = baseManifest();
  manifest.gates[0].cases[0].required = { exitCode: 7, outputPattern: 'META_REJECT' };
  manifest.gates[0].cases[0].actual = { outputPattern: 'META_REJECT', exitCode: 7 };
  await writeManifest(root, manifest);

  const result = verify(root);
  assert.equal(result.status, 0, output(result));
  assert.doesNotMatch(output(result), /behavior delta requires|DEFECT \(owner:/);
});

test('a required-versus-actual delta without a tracked owner is rejected', async () => {
  const root = await fixture('ownerless-delta');
  await writeGate(root, '#!/bin/sh\nexit 0\n');
  const manifest = baseManifest();
  manifest.gates[0].inertMutation.find = 'exit 0';
  manifest.gates[0].inertMutation.replace = 'exit 7';
  manifest.gates[0].cases[0].actual.exitCode = 0;
  await writeManifest(root, manifest);

  const result = verify(root);
  assert.notEqual(result.status, 0);
  assert.match(output(result), /meta-fixture.*delta.*tracked owner/i);
});

test('moving criterion bindings to unrelated cases is rejected', async () => {
  const root = await fixture('semantic-misbinding');
  await writeGate(root);
  const manifest = baseManifest();
  manifest.criteria.push({
    id: 'META-CRIT-2',
    originalText: 'The fixture reports the second rejection reason.',
    currentText: 'The fixture reports the second rejection reason.',
    claimType: 'integrity',
    source: 'fixture',
    meaningChanges: [],
    caseRefs: ['meta-fixture/rejects-second-input'],
  });
  manifest.gates[0].cases.push({
    ...manifest.gates[0].cases[0],
    id: 'rejects-second-input',
    criterionIds: ['META-CRIT-1'],
  });
  manifest.gates[0].cases[0].criterionIds = ['META-CRIT-2'];
  await writeManifest(root, manifest);

  const result = verify(root);
  assert.notEqual(result.status, 0);
  assert.match(output(result), /META-CRIT-1.*rejects-bad-input.*not bound/i);
  assert.match(output(result), /META-CRIT-2.*rejects-second-input.*not bound/i);
});

test('moving meaning and prose criteria to an unrelated type error is rejected', async () => {
  const root = await fixture('real-manifest-misbinding');
  const manifest = JSON.parse(
    await readFile(path.join(process.cwd(), 'gates', 'gates.manifest.json'), 'utf8'),
  );
  for (const gate of manifest.gates) {
    for (const gateCase of gate.cases) {
      gateCase.criterionIds = gateCase.criterionIds.filter(
        (id) => !['RM02-MEANING-PROVENANCE', 'RM02-PROSE-CONTROL'].includes(id),
      );
    }
  }
  const typeError = manifest.gates
    .find((gate) => gate.id === 'quality-typecheck')
    .cases.find((gateCase) => gateCase.id === 'type-error');
  typeError.criterionIds.push('RM02-MEANING-PROVENANCE', 'RM02-PROSE-CONTROL');
  await writeManifest(root, manifest);

  const result = verify(root, ['--structure-only']);
  assert.notEqual(result.status, 0);
  assert.match(output(result), /RM02-MEANING-PROVENANCE.*missing-meaning-provenance.*not bound/i);
  assert.match(output(result), /RM02-PROSE-CONTROL.*prose-claim-misbinding.*not bound/i);
  assert.match(
    output(result),
    /RM02-(?:MEANING-PROVENANCE|PROSE-CONTROL).*undeclared exercising case quality-typecheck\/type-error/i,
  );
});

test('a criterion with no bound case is rejected', async () => {
  const root = await fixture('unbound-criterion');
  await writeGate(root);
  const manifest = baseManifest();
  manifest.criteria.push({
    id: 'ORPHAN',
    originalText: 'This criterion is not exercised.',
    currentText: 'This criterion is not exercised.',
    claimType: 'quality',
    source: 'fixture',
    meaningChanges: [],
  });
  await writeManifest(root, manifest);

  const result = verify(root);
  assert.notEqual(result.status, 0);
  assert.match(output(result), /ORPHAN.*no bound case/i);
});

test('an unbound governing prose marker is rejected', async () => {
  const root = await fixture('unbound-prose');
  await writeGate(root);
  await mkdir(path.join(root, 'docs'), { recursive: true });
  await writeFile(path.join(root, 'docs', 'governing.md'), 'GATE-CLAIM:UNBOUND\n');
  const manifest = baseManifest();
  manifest.governingClaimFiles = ['docs/governing.md'];
  await writeManifest(root, manifest);

  const result = verify(root);
  assert.notEqual(result.status, 0);
  assert.match(output(result), /GATE-CLAIM:UNBOUND.*unbound/i);
});

test('directly contradictory modeled scenarios are rejected', async () => {
  const root = await fixture('conflict');
  await writeGate(root);
  const manifest = baseManifest();
  manifest.compatibilityScenarios = [
    {
      id: 'ONE',
      construction: 'same-input',
      caseRefs: ['meta-fixture/rejects-bad-input'],
      invocation: ['sh', '-c', 'exit 0'],
      expected: { exitCode: 0 },
    },
    {
      id: 'TWO',
      construction: 'same-input',
      caseRefs: ['meta-fixture/rejects-bad-input'],
      invocation: ['sh', '-c', 'exit 1'],
      expected: { exitCode: 1 },
    },
  ];
  await writeManifest(root, manifest);

  const result = verify(root);
  assert.notEqual(result.status, 0);
  assert.match(output(result), /ONE.*TWO.*conflict/i);
});

test('compatibility scenarios execute referenced conditions as one construction', async () => {
  const root = await fixture('combined-compatibility');
  await writeGate(root);
  const manifest = baseManifest();
  manifest.gates[0].cases.push({
    id: 'second-condition',
    criterionIds: ['META-CRIT-1'],
    mustFail: true,
    invocation: ['sh', '-c', 'echo "$SECOND_REASON" >&2; exit 7'],
    fixture: { writeFiles: [{ path: 'conditions/second', content: 'present\n' }] },
    required: { exitCode: 7 },
    actual: { exitCode: 7 },
    reasonPattern: 'SECOND_REASON',
    environment: { SECOND_REASON: 'SECOND_REASON' },
  });
  manifest.criteria[0].caseRefs.push('meta-fixture/second-condition');
  manifest.gates[0].cases[0].fixture = {
    writeFiles: [{ path: 'conditions/first', content: 'present\n' }],
  };
  manifest.compatibilityScenarios = [
    {
      id: 'BOTH-CONDITIONS',
      construction: 'both-fixtures',
      caseRefs: ['meta-fixture/rejects-bad-input', 'meta-fixture/second-condition'],
      invocation: ['sh', '-c', 'test -f conditions/first && test -f conditions/second'],
      expected: { exitCode: 0 },
    },
  ];
  await writeManifest(root, manifest);

  const result = verify(root);
  assert.equal(result.status, 0, output(result));
  assert.match(output(result), /COMPATIBILITY BOTH-CONDITIONS: observed expected outcome/i);
});

test('a restated criterion without provenance is rejected', async () => {
  const root = await fixture('provenance');
  await writeGate(root);
  const manifest = baseManifest();
  manifest.criteria[0].currentText = 'The fixture rejects only malformed input.';
  await writeManifest(root, manifest);

  const result = verify(root);
  assert.notEqual(result.status, 0);
  assert.match(output(result), /META-CRIT-1.*meaning-change provenance/i);
});

test('a security criterion bound only to a positive case is unregistered in substance', async () => {
  const root = await fixture('positive-only-criterion');
  await writeGate(root);
  const manifest = baseManifest();
  manifest.criteria.push({
    id: 'POSITIVE-ONLY',
    originalText: 'A security property.',
    currentText: 'A security property.',
    claimType: 'security',
    source: 'fixture',
    meaningChanges: [],
  });
  manifest.gates[0].cases.push({
    id: 'positive-only',
    criterionIds: ['POSITIVE-ONLY'],
    mustFail: false,
    invocation: ['gates/meta-fixture.sh'],
    required: { exitCode: 7 },
    actual: { exitCode: 7 },
    reasonPattern: '',
  });
  await writeManifest(root, manifest);

  const result = verify(root);
  assert.notEqual(result.status, 0);
  assert.match(output(result), /POSITIVE-ONLY.*no must-fail case/i);
});

test('a registered prose claim whose marker is absent is rejected', async () => {
  const root = await fixture('missing-prose-marker');
  await writeGate(root);
  await mkdir(path.join(root, 'docs'), { recursive: true });
  await writeFile(path.join(root, 'docs', 'governing.md'), 'No marker here.\n');
  const manifest = baseManifest();
  manifest.governingClaimFiles = ['docs/governing.md'];
  manifest.proseClaims = [{ id: 'MISSING-MARKER', criterionId: 'META-CRIT-1' }];
  await writeManifest(root, manifest);

  const result = verify(root);
  assert.notEqual(result.status, 0);
  assert.match(output(result), /GATE-CLAIM:MISSING-MARKER.*missing/i);
});

test('source-versus-deployed byte drift is rejected and names the gate', async () => {
  const root = await fixture('deployment-drift');
  await writeGate(root);
  await mkdir(path.join(root, 'deployed'), { recursive: true });
  await writeFile(path.join(root, 'deployed', 'meta-fixture.sh'), '#!/bin/sh\nexit 0\n');
  const manifest = baseManifest();
  manifest.gates[0].deployment = { kind: 'file', path: 'deployed/meta-fixture.sh' };
  await writeManifest(root, manifest);

  const result = verify(root);
  assert.notEqual(result.status, 0);
  assert.match(output(result), /meta-fixture.*source.*deployed.*drift/i);
});

test('deployment drift meta-control fails if the shared comparator is made inert', async () => {
  const root = await fixture('deployment-comparator-inert');
  await writeGate(root);
  await mkdir(path.join(root, 'deployed'), { recursive: true });
  await copyFile(
    path.join(root, 'gates', 'meta-fixture.sh'),
    path.join(root, 'deployed', 'meta-fixture.sh'),
  );
  const manifest = baseManifest();
  manifest.gates[0].deployment = { kind: 'file', path: 'deployed/meta-fixture.sh' };
  await writeManifest(root, manifest);

  const alteredScripts = path.join(root, 'verifier-scripts');
  await mkdir(alteredScripts, { recursive: true });
  const verifierSource = await readFile(verifier, 'utf8');
  const inertSource = verifierSource.replace(
    'return source.equals(deployed);',
    'return true; // deliberate test-only inert comparator',
  );
  assert.notEqual(inertSource, verifierSource, 'shared deployment comparator mutation went stale');
  await writeFile(path.join(alteredScripts, 'gate-verify.mjs'), inertSource);
  await copyFile(
    path.join(process.cwd(), 'scripts', 'gate-history.mjs'),
    path.join(alteredScripts, 'gate-history.mjs'),
  );

  const result = spawnSync(
    process.execPath,
    [
      path.join(alteredScripts, 'gate-verify.mjs'),
      '--root',
      root,
      '--manifest',
      'gates/gates.manifest.json',
      '--skip-history',
    ],
    { cwd: root, encoding: 'utf8', env: { ...process.env, HOME: os.homedir() } },
  );
  assert.notEqual(result.status, 0);
  assert.match(output(result), /meta-fixture.*drift negative control was ineffective/i);
});